CN1711649B - Light emitting device and fabrication method thereof - Google Patents
Light emitting device and fabrication method thereof Download PDFInfo
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- CN1711649B CN1711649B CN200380103411.3A CN200380103411A CN1711649B CN 1711649 B CN1711649 B CN 1711649B CN 200380103411 A CN200380103411 A CN 200380103411A CN 1711649 B CN1711649 B CN 1711649B
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Abstract
The present invention discloses a light device and a fabrication method thereof. An object of the present invention is to provide the light device and the fabrication method thereof an electric/thermal/structural stability is obtained, and a P-type electrode and an N-type electrode can be simultaneously formed. In order to achieve the above object, the inventive light device includes: a GaN-based layer; a high concentration GaN-based layer formed on the GaN-based layer; a first metal-Ga compound layer formed on the high concentration GaN-based layer; a first metal layer formed on the first metal-Ga compound layer; a third metal -Al compound layer formed on the first metal layer; and a conductive oxidation preventive layer formed on the third metal-Al compound layer.
Description
Technical field
The present invention relates to a kind of optical device, and relate more specifically to a kind of optical device and manufacture method thereof, wherein can obtain electricity/heat/stability of structure, and P type electrode and N type electrode can be formed simultaneously.
In addition, the present invention relates to a kind of optical device, relate more specifically to a kind of optical device and manufacture method thereof, wherein the feature contact resistance is lowered, and the charge carrier that provides from the outside not only can use the diffusion of electric current to device of the contact resistance executing rule of described reduction, and the photon that the active layer from described device produces and sends can escape into the outside well.
In addition, the present invention relates to a kind of optical device, relate more specifically to a kind of optical device and manufacture method thereof, wherein the metal-hydrogen compound is formed, to implement the Ohmic electrode of P type based on the compound semiconductor of gallium nitride.
Background technology
Usually, in order to implement optical device such as light-emitting diode or laser, good ohmic contact should at first be formed in semiconductor and form between the metal of electrode.
In addition, need the surface state of complanation, thermal stability is easy to handle low contact resistance, high output, good anti-corrosive properties etc.
Simultaneously, the nitride semiconductor photogenerator based on GaN mainly is grown on sapphire substrate or carborundum (SiC) substrate.In addition, polycrystal layer based on GaN is grown on described sapphire substrate or the SiC substrate as resilient coating with low growth temperature, and unadulterated afterwards GaN layer, the N type GaN layer of doped silicon (Si), the N type that perhaps has combining structure is formed on the described resilient coating with high temperature based on the GaN layer.After this, luminescent layer (active layer with quantum well structure) is formed on described N type based on the GaN layer, and the P type is additionally formed on described luminescent layer based on the GaN layer, thereby described light emitting semiconductor device is manufactured.
In addition, in described light emitting semiconductor device, transparency electrode can form with following method.
At first, with reference to the concise and to the point P type electrode structure that is formed in traditional luminescent device of describing of Fig. 1.
Fig. 1 is the view of the typical P type electrode of the traditional luminescent device of explanation.
The P type electrode of the luminescent device shown in Fig. 1 is constructed to have the P type transparent electrode layer 102 that is formed on the P type GaN layer 101, and has the P type bonding electrodes 103 that is formed on the described P type transparent electrode layer 102.The electrode structure of last surface construction is convenient ' sealing ' electrode structure that is known as.
Under the situation of described ' sealing ' electrode structure, described P type transparent electrode layer 102 mainly is to be formed by the Ni/Au layer.In addition, described P type bonding electrodes 103 is to comprise except that Al and Cr two or more metals based on Au () individual layer for example, Au, Ti, Ni, In and Pt, the perhaps sandwich construction of two or more a plurality of layers.That is to say that it is Au, Ni/Au, Ti/Au or Pt/Au layer etc.
For example, as shown in Figure 2, a metal is by from by Ni, Pt, Ti selects in the group that Cr and Au form to deposit the first metal layer 102a on the layer 101 of described P type based on GaN, and gold (Au) is used to deposit the second metal level 102b, thereby transparency electrode 102 can be formed.As the exemplary of described transparency electrode, the Ni/Au electrode is used.
Perhaps, as shown in Figure 3, the first metal layer 102c that is used to form good oxide be formed on the P type based on the layer 101 of GaN and subsequently, after for example gold (Au) is deposited, in oxygen-containing atmosphere, carry out thermal annealing at the second metal level 102d that is used for the charge carrier conduction.
As typical example, a kind of method is arranged, wherein cobalt (Co) and gold (Au) sequentially be deposited on described P type based on the layer 101 of GaN on after, described thermal annealing is performed in oxygen-containing atmosphere to form ' Co-O ' oxide.Perhaps, a kind of use nickel (Ni) replaces the method for cobalt (Co) also to be suggested.
Therefore, metal oxide layer 102e is formed to have the transparency, so that transparency electrode 102 is formed on the layer 101 of P type based on GaN.
The conventional P type electrode of luminescent device also can be configured as shown in Figure 4, and Fig. 4 is the view of another typical P type electrode of the described traditional luminescent device of explanation.
The P type electrode of luminescent device as shown in Figure 4 is configured, and having on P type GaN layer 201 the P type transparent electrode layer 202 that forms, and has the P type bonding electrodes 203 that is formed on the described P type transparent electrode layer 202.At this moment, transparent electrode layer 202 is constructed to have the part of the P type bonding electrodes 203 that is filled in therebetween.
The electrode structure of last surface construction is convenient ' opening ' electrode structure that is known as.
Under the situation of described ' opening ' electrode structure, comprise that the structure of Cr or Al layer is suggested to improve joint capacity, and be formed have with the similar structure of described ' sealing ' electrode structure.
Simultaneously, Fig. 5 is the view of the typical N type electrode of the traditional luminescent device of explanation.
Luminescent device is constructed to have the N type electrode layer 302 that is formed on the N type GaN layer 301 as shown in Figure 5.
Under the situation of described N type electrode layer 302, proposition be to use Ti, Al, the electrode of the electrode of the single-layered of Au or the multiple stratification of two or more layers.
But under the situation of structurized in the above P type electrode, the feature contact resistance is much larger than 10-3 Ω cm
2, reason is high-resistance P type GaN layer.
In addition, be known that in the transparent electrode structure that is not oxide structure (referring to Fig. 2), because the feature contact resistance has 10
-2Ω cm
2High like that, ' the current spread device ' of one of major function of described transparency electrode is inoperative in the process of device operation.
Be known that the high feature contact resistance owing to described interface, it is serving as thermal source at the interface when device operation, thereby the reduction of device reliability is directly caused very big influence.
In addition, reported that the transparent electrode structure that is formed by the described manufacture method of reference Fig. 3 has the feature contact resistance of remarkable improvement, but known its mis-behave aspect transmittance.Known this owing to metal oxide is ' polycrystalline ' structure during thermal annealing in oxygen-containing atmosphere, rather than help to improve ' heteroepitaxy (heteroepitaxial) ' structure of transmission, a lot of undersized particles are present in the described transparency electrode, cause the absorption or the scattering loss of the photon that sends from described semiconductor.
In addition, in order to implement the Ohmic electrode of quality in the structure in the above, described charge carrier should can carry out having greater than 10 in the doped region of charge carrier tunnelling therein
18Cm
-3Concentration, but in fact the P type reaches 10 based on the carrier concentration of the compound semiconductor of gallium nitride is low
17Cm
-3
Like this, this low carrier concentration makes schottky barrier height increase between described metal and the described semiconductor at the interface feature contact resistance, causes bad ohm property.
In addition, be present in the P type and cause when the described thermal annealing between described metal and described semiconductor reacting to each other at the interface based on the lip-deep natural oxide layer of the compound semiconductor of gallium nitride, thereby cause leakage current to increase, reverse breakdown voltage reduces, a lot of shortcomings such as unusual threshold voltage characteristic, and the result is reduced in device reliability and life-span.
In addition, above-mentioned defective all exists in all comprise the luminescent device of open electrode structure and enclosed type electric electrode structure P type electrode.Therefore, need exploitation to have the P type electrode of high thermal stability and low contact resistance vividly.
In addition, have greater than 10
-5Ω cm
2The N type electrode of feature contact resistance be suitable for described luminescent device, but that the electrode that is based on Ti is reported in the thermal characteristics aspect is very fragile.
In addition, because P type electrode and N type electrode are manufactured separately, described conventional art has a lot of shortcomings aspect device production and the output.
Summary of the invention
Therefore, the present invention points to basic elimination because the restriction of correlation technique and a kind of optical device and the manufacture method thereof of one or more problem that shortcoming causes.
An object of the present invention is to provide a kind of optical device and manufacture method thereof, wherein electricity/heat/stability of structure is obtained, and P type electrode and N type electrode can be formed simultaneously.
Another object of the present invention provides a kind of optical device and manufacture method thereof, wherein the feature contact resistance of transparency electrode is lowered, and the regular current that the charge carrier that provides from the outside not only can use the resistance of described reduction to carry out device is propagated, and the photon that produces and send from this device can escape into the outside well.
A further object of the present invention provides a kind of optical device and manufacture method thereof, wherein the metal-hydrogen compound layer is formed in the Ohmic electrode of P type based on the compound semiconductor of gallium nitride, and native oxide layer is removed and makes low resistance, high transmission, and high thermal stability can be implemented.
In order to obtain these and other the advantage as the purpose according to the present invention that is realized and broadly describe, optical device according to an aspect of the present invention comprises: based on the layer of GaN; Be formed on described based on the layer of the high concentration on the layer of GaN based on GaN; Be formed on described high concentration based on the first metal-Ga compound layer on the layer of GaN; Be formed on the first metal layer on described first metal-Ga compound layer; Be formed on the 3rd metal-Al compound layer on the described the first metal layer; And the antioxidation coating that is formed on the conduction on described the 3rd metal-Al compound layer.
In another was implemented, a kind of optical device comprised: based on the layer of GaN; Be formed on described based on the layer of the high concentration on the layer of GaN based on GaN; Be formed on described high concentration based on the transparent electrode layer on the layer of GaN; Be formed on the first metal-Ga compound layer on the described transparent electrode layer; Be formed on the first metal layer on described first metal-Ga compound layer; Be formed on the 3rd metal-Al compound layer on the first metal layer; And the antioxidation coating that is formed on the conduction on described the 3rd metal-Al compound layer.
One implementing, a kind of optical device comprises: based on the layer of GaN again; Be formed on described based on the layer of the high concentration on the layer of GaN based on GaN; Be formed on described high concentration based on the first metal-Ga-N compound layer on the layer of GaN; Be formed on the first metal layer on described first metal-Ga-N compound layer; Be formed on the 3rd metal-Al compound layer on the described the first metal layer; And the antioxidation coating that is formed on the conduction on described the 3rd metal-Al compound layer.
In addition, described based on GaN the layer be the P type or the N type.
In another was implemented, a kind of optical device had transparency electrode, and wherein said transparency electrode comprises: the metal oxide layer that is formed by first metal; React the mixed oxide layer that forms by the 3rd metal and first metal that forms described metal oxide layer; And the conduction material arranged, it is formed by second metal, and is arranged in described metal oxide layer and the described mixed oxide layer with metal dots shape.
In another was implemented, a kind of optical device comprised: semiconductor layer; Be formed on the high concentration impurities metal oxide layer on the described semiconductor layer; And be formed on transparency electrode on the described high concentration impurities metal oxide layer.
In another was implemented, a kind of optical device had an electrode structure, and wherein said electrode structure comprises: based on the layer of GaN; Be formed on the upper surface of described layer based on GaN and have contact layer with the high response of hydrogen; Be formed on the upper surface of described contact layer and have joint sheet (bonding pad) layer with the hypoergia of oxygen; Be formed on the diffusion diffusion impervious layer at the interface of described contact layer and described joint sheet layer; And by natural reaction and/or thermal annealing process be formed on described contact layer and described based on GaN the layer high concentration at the interface based on GaN the layer and the metal-hydrogen compound layer.
In another aspect of this invention, the step that a kind of manufacture method of optical device comprises is: first based on GaN the layer and second based on GaN layer on form the first metal layer; On described the first metal layer, form by based on the Al or second metal level that forms based on the material of (Ni-Al); On described second metal level, form the 3rd metal level; On described the 3rd metal level, form the antioxidation coating of conduction; And the material as the result of preceding step carried out thermal annealing, make described first based on GaN the layer and second based on GaN the layer upper area respectively by high concentration first based on GaN the layer and high concentration second based on GaN the layer form, the described high concentration first that is formed on first metal-Ga compound layer goes up based on the layer of GaN and first metal-Ga-N compound layer is formed on the layer of described high concentration second based on GaN, the first metal layer is formed on described first metal-Ga compound layer and the first metal-Ga-N compound layer, the 3rd metal-Al compound layer is formed on the described the first metal layer, and the antioxidation coating of conduction is formed on described the 3rd metal-Al compound layer.
In another was implemented, the step that a kind of optical device manufacturing method comprises was: form the first metal layer on the layer based on GaN; On described the first metal layer, form second metal level; On described second metal level, form the 3rd metal level; And in oxygen-containing atmosphere, the material as a result as preceding step is carried out thermal annealing, the upper area that makes described layer based on GaN is a high concentration based on the layer of GaN, the first metal layer is a metal oxide layer, first metal reaction of the 3rd metal level and formation the first metal layer is to form mixed oxide layer, and described second metal level is the conduction material arranged of the metal dots shape in described metal oxide layer and described mixed oxide layer.
In another was implemented, the step that a kind of manufacture method of optical device comprises was: remove the native oxide layer based on the compound semiconductor of GaN; Good reactive metal that use has with hydrogen deposits contact layer; The metal that use has with the hypoergia of oxygen forms joint sheet layer and forms stable compound with described contact layer; And execution thermal annealing.
Description of drawings
Fig. 1 is the view of the typical P type electrode of the traditional luminescent device of explanation;
Fig. 2 is the view of P type electrode of typical many structures of the traditional luminescent device of explanation;
Fig. 3 is the view of P type electrode of another typical many structures of the traditional luminescent device of explanation;
Fig. 4 is the view of another typical P type electrode of the traditional luminescent device of explanation;
Fig. 5 is the view of the typical N type electrode of the traditional luminescent device of explanation;
Fig. 6 is the view according to the P type electrode of the luminescent device of the first embodiment of the present invention;
Fig. 7 is the view of the P type electrode of luminescent device according to a second embodiment of the present invention;
Fig. 8 is the view of structure of the luminescent device with transparency electrode of a third embodiment in accordance with the invention;
Fig. 9 is the view of structure of the luminescent device with transparency electrode of a fourth embodiment in accordance with the invention;
Figure 10 is the view of the structure of the luminescent device with transparency electrode according to a fifth embodiment of the invention;
Figure 11 is the view of the structure of the luminescent device with transparency electrode according to a sixth embodiment of the invention;
Figure 12 illustrates that according to a seventh embodiment of the invention the P type with the metal-hydrogen compound layer that formed is based on the compound (p-(Al) of gallium nitride before thermal annealing
x(In)
y(Ga)
1-(x+y)N) sectional view of semi-conductive Ohmic electrode;
Figure 13 illustrates that P type after according to a seventh embodiment of the invention the thermal annealing is based on the compound (p-(Al) of gallium nitride
x(In)
y(Ga)
1-(x+y)N) sectional view of the structure of semi-conductive Ohmic electrode;
Figure 14 is the view that the typical N type electrode of luminescent device according to a preferred embodiment of the invention is described;
Figure 15 is the view of manufacture method of describing the transparency electrode of luminescent device according to a preferred embodiment of the invention;
Figure 16 is the result's of the explanation SIMS depth analysis that is used to confirm platinum-hydrogen compound layer that the first Ohmic electrode formation method of the luminescent device by according to a preferred embodiment of the invention forms a chart;
Figure 17 is the result's of the explanation SIMS depth analysis that is used to confirm titanium-hydrogen compound layer that the first Ohmic electrode formation method of the luminescent device by according to a preferred embodiment of the invention forms a chart;
Figure 18 is the view that the I-E characteristic of the Ohmic electrode that the second Ohmic electrode formation method of luminescent device according to a preferred embodiment of the invention makes is used in explanation;
Figure 19 illustrates that thermal annealing is wherein formed the view of the I-E characteristic of the Ohmic electrode that method carries out by the 3rd Ohmic electrode of according to a preferred embodiment of the invention luminescent device;
Figure 20 is the view that the characterization contact resistance depends on the result of the thermal annealing time lapse in the 3rd Ohmic electrode formation method of luminescent device according to the preferred embodiment of the invention;
Figure 21 is the view that the I-E characteristic of the Ohmic electrode that the 4th Ohmic electrode formation method of luminescent device according to a preferred embodiment of the invention makes is used in explanation;
Figure 22 illustrates that thermal annealing is wherein formed the view of the I-E characteristic of the Ohmic electrode that method carries out by the 5th Ohmic electrode of according to a preferred embodiment of the invention luminescent device;
Figure 23 is the result's of the explanation feature contact resistance that relies on the thermal annealing time lapse in the 5th Ohmic electrode formation method of luminescent device according to the preferred embodiment of the invention a view;
Figure 24 is the view of variation that the sheet resistance value of Ohmic electrode according to a preferred embodiment of the invention is described;
Figure 25 is a view of describing the electrode manufacturing method of luminescent device according to another embodiment of the present invention.
Embodiment
Hereinafter, will describe the preferred embodiments of the present invention in conjunction with the accompanying drawings in detail.Here, about distributing same reference number by a pair of element formed, and each of described centering uses English alphabet to divide again.
At first, with the electrode structure of the luminescent device briefly describing among the present invention to be proposed, and will make detailed description according to the manufacture method of luminescent device of the present invention.
Fig. 6 is the view according to the P type electrode of the luminescent device of the first embodiment of the present invention.
As shown in Figure 6, the luminescent device of being invented has P
+-(In, Al) GaN layer 402 is formed on P-as the high hole concentration layer (In is Al) on the GaN layer 401.In addition, first metal-Ga compound layer 403 is formed on described P
+-(In, Al) on the GaN layer 402, and the first metal layer 404 is formed on described first metal-Ga compound layer 403.In addition, the 3rd metal-Al compound layer 405 is formed on the described the first metal layer 404, and the antioxidation coating 406 of conduction is formed on described the 3rd metal-Al compound layer 405.This representative is corresponding to the P type electrode structure of traditional ' opening ' electrode structure.
Fig. 7 is the view of the P type electrode of luminescent device according to a second embodiment of the present invention.
As shown in Figure 7, described luminescent device according to a second embodiment of the present invention has P
+-(In, Al) GaN layer 402 is formed on P-as the high hole concentration layer (In, Al) on the GaN layer 401, and P type transparent electrode layer 410 is formed on described P by additional
+-(In is Al) on the GaN layer 402.
In addition, first metal-Ga compound layer 403 is formed on the described P type transparent electrode layer 410, and the first metal layer 404 is formed on described first metal-Ga compound layer 403.
In addition, the 3rd metal-Al compound layer 405 is formed on the described the first metal layer 404, and the antioxidation coating 406 of conduction is formed on described the 3rd metal-Al compound layer 405.This representative is corresponding to the P type electrode structure of tradition ' sealing ' electrode structure.
Fig. 8 is the view of structure of the luminescent device with transparency electrode of a third embodiment in accordance with the invention.
As shown in Figure 8, be metal oxide layer 503 according to the transparency electrode 510 of luminescent device of the present invention, mixed oxide layer 504 and conduction material arranged 505.In addition, described transparency electrode 510 be formed on high concentration P type based on GaN the layer 502 on, and described high concentration P type based on GaN the layer 502 be formed on described P type based on GaN the layer 501 on.
Here, described conduction material arranged 505 is arranged in the whole transparency electrode of being made up of described metal oxide layer 503 and described mixed oxide layer 504 510 has metal dots shape, and serves as ' conducting bridge '.At this moment, described conduction material arranged 505 is arranged to the metal dots shape with periodic arrangement in the described transparency electrode 510.
On the other hand, as another example according to the transparency electrode of luminescent device of the present invention, the transparency electrode of described luminescent device also can be formed as shown in Fig. 9 to 11.
Fig. 9 to 11 is explanation views according to the structure of the luminescent device with transparency electrode of the 4th to the 6th embodiment of the present invention.
As shown in Figure 9, the transparency electrode of a fourth embodiment in accordance with the invention has P
+-IrO layer 602, it has high hole concentration (greater than 10
18Cm
-3) be formed on the layer 601 of P type based on GaN, and be formed on described P
+Transparency electrode 603 on the-IrO layer 602.Here, described transparency electrode 603 can be formed by some metal transparency electrode (for example, Co-O/Au, Ni-O/Au etc.), and can be by forming with reference to figure 8 described transparency electrodes.
Here, described P
+-IrO layer 602 can form with following method.
A kind of method is to use the deposition process of sputtering system, and the oxygen containing gaseous plasma that wherein is used for IrO or Ir target is carried out deposition.
In other method, described P
+-IrO layer 602 also can form by evaporator or physical vapor deposition (PVD) method deposition Ir, and carries out described thermal annealing at least 400 ℃ high temperature subsequently in oxygen-containing atmosphere.At this moment, described oxide self has ' p-conduction '.
In addition, as shown in Figure 10, described transparency electrode according to a fifth embodiment of the invention has P
+-ZnO layer 702, it has high hole concentration (greater than 10
18Cm
-3) be formed on the layer 701 of P type based on GaN, and transparency electrode 703 is formed on described P
+On-IrO the layer 702.Here, described transparency electrode 703 can be the metal with good electric conductivity and transmitance, and can be formed by the transparency electrode of describing with reference to figure 8.
Here, as the formation method, described P
+-IrO layer 702 can use sputter, MBE (molecular beam epitaxy), MOVCD (metal oxide chemical vapor deposition) and forming.In this case, phosphorus is used as dopant.
In the situation of described sputter, described high concentration P type ZnO can use oxygen-containing gas plasma and the PH that is used for the ZnO target
3Deposit, and under the situation of described MOVCD, described high concentration P type ZnO can use ZnCl
2, O
2And PH
3Grow.
In addition, as shown in Figure 11, transparency electrode according to a sixth embodiment of the invention has and is formed on layer the high concentration N 801 on of P type based on GaN
+-ZnO layer 802, and transparency electrode 803 is formed on described N
+On-IrO the layer 802.Wherein, described transparency electrode 803 can be the metal with good electric conductivity and transmitance, and can be formed by the described transparency electrode of reference Fig. 8.
As N
+-ZnO layer 802 formation method, sputter deposition is used, and the MOCVD method also is considered.
In the method for described use sputter, at first, if ZnO, Al
2O
3Target is used to form plasma and is used for deposition in described oxygen-containing atmosphere, Al serves as ZnO interior ' agent of N conductiving doping ' with deposition high concentration ZnO.
As the more definite expression of ZnO that as above forms, described ZnO is expressed as ZnO:Al or AZO (ZnO of doped with Al).
Characteristic below the invention described above can obtain.
Has high hole concentration (greater than 10
18Cm
-3) described P
+Type IrO 602 or described P
+Type ZnO 702 is formed on the layer 601 or 701 of described P type based on GaN, so that be formed on described P
+Type IrO 602 or described P
+Transparency electrode 603 on the type ZnO 702 or 703 can easily obtain ohmic contact by the tunnelling operation principle.
That is to say that described IrO with high-concentration dopant and ZnO serve as about forming the tunnel layer of transparent electrode layer thereon, make the described good ohmic contact can be obtained.
If known described doping content increases, because described charge carrier flows by tunnelling and do not consider metal semiconductor barrier, described ohmic contact is formed naturally.
In addition, even at N
+Under the situation that type ZnO layer 802 is formed, can realize by described tunnelling operation principle with the ohmic contact of the transparency electrode 803 that forms on it.
Figure 12 illustrates that according to a seventh embodiment of the invention the P type with the metal-hydrogen compound layer that formed is based on the compound (p-(Al) of gallium nitride before thermal annealing
x(In)
y(Ga)
1-(x+y)N) sectional view of semi-conductive Ohmic electrode;
Referring to Figure 12, that stacked is the compound (p-(Al) of P type based on gallium nitride
x(In)
y(Ga)
1-(x+y)N) semiconductor layer 901, contact layer 904 and joint sheet layer 905.
Before described contact layer 904 is formed, if at the compound (p-(Al) of P type based on gallium nitride
x(In)
y(Ga)
1-(x+y)N) metal that forms described contact layer 904 after semi-conductive native oxide layer is removed is deposited, and the metal of the described contact layer 904 of so described formation and described P type are based on the compound (p-(Al) of gallium nitride
x(In)
y(Ga)
1-(x+y)N) hydrogen in the semiconductor is in conjunction with forming metal-hydrogen compound layer 903, and the P on the lower surface of described metal-hydrogen compound layer 903
+Type is based on the compound (p of gallium nitride
+-(Al)
x(In)
y(Ga)
1-(x+y)N) semiconductor layer 902.
Described contact layer 904 can be formed by individual layer or multilayer, and can be platinum (Pt), titanium (Ti), palladium (Pd), nickel (Ni), tantalum (Ta), tungsten (W), aluminium (Al), chromium (Cr), vanadium (V), iridium (Ir), hafnium (Hf) and cobalt (Co).
In addition, described joint sheet layer 905 can be formed by individual layer or multilayer, and can be gold (Au), palladium (Pd), ruthenium (Ru), nickel (Ni), tungsten (W), cobalt (Co), molybdenum (Mo) and copper (Cu).
In addition, when an element of the described joint sheet layer 905 of supposition is ' M ', M-O (' M ' oxygen compound) so, M-Si (' M ' silicon compound), M-N (' M ' nitrogen compound) and M-C (' M ' carbon compound) also can be formed.
In addition, described metal-hydrogen compound layer 903 is formed, and makes the compound (p-(Al) of P type based on gallium nitride
x(In)
y(Ga)
1-(x+y)N) semi-conductive charge carrier can be increased the height that is present in described metal and described semi-conductive schottky barrier height at the interface with reduction.
On the other hand, described P type is based on the compound (p-(Al) of gallium nitride
x(In)
y(Ga)
1-(x+y)N) native oxide layer in the semiconductor is used for etched chemical substance by use or plasma source is removed.Especially, when described chemical substance is used, fluorine (F), chlorine (Cl), sulphur (S), the passivation of the element of hydroxy (OH) etc. is formed on the P type wafer to promote the reaction of the hydrogen of described metal and described P type wafer when the plated metal element.Preferably, as described chemical substance, BOE (oxide etching of buffering) solution is used.
Figure 13 is the P after the thermal annealing that illustrates according to a seventh embodiment of the invention
+Type is based on the compound (p of gallium nitride
+-(Al)
x(In)
y(Ga)
1-(x+y)N) view of the structure of semi-conductive Ohmic electrode;
Referring to Figure 13, different with Figure 12, diffusion impervious layer 910 is additionally formed between described joint sheet layer 905 and described contact layer 904 by thermal annealing, and P
+Type is based on the compound (p of gallium nitride
+-(Al)
x(In)
y(Ga)
1-(x+y)N) semiconductor layer 902 and metal-hydrogen compound layer 903 are formed deeplyer.
Described diffusion impervious layer 910 is by forming with described joint sheet layer 905 and reacting to each other of described contact layer 904, and the undesirable reaction between described metal and the described semiconductor is suppressed.
In addition, described thermal annealing has promoted contact layer 904 and the P type compound (p-(Al) based on gallium nitride
x(In)
y(Ga)
1-(x+y)N) reaction of semiconductor 901 is so that the active reaction of the metal of described contact layer and hydrogen causes P
+Type is based on the compound (p of gallium nitride
+-(Al)
x(In)
y(Ga)
1-(x+y)N) semiconductor layer 902 and metal-hydrogen compound layer 903 are formed deeplyer, thereby more increase described carrier concentration.The result is that better Ohmic electrode is implemented.
On the other hand, Figure 14 is the view that the typical N type electrode of luminescent device according to a preferred embodiment of the invention is described.
In another example according to luminescent device of the present invention, as shown in figure 14, N
+-(In, Al) GaN layer 1002 is formed on N-(In is Al) on the GaN layer 1001.In addition, first metal-Ga-N compound layer 1003 is formed on described N
+-(In, Al) on the GaN layer 1002, and the first metal layer 1004 is formed on described first metal-Ga-N compound layer 1003.
In addition, the 3rd metal-Al compound layer 1005 is formed on the described the first metal layer 1004, and the antioxidation coating 1006 of conduction is formed on the 3rd metal-Al compound layer 1005.
Therefore, the electrode forming process of last surface light-emitting device is referenced Figure 15 to 25 and describes.
Figure 15 is the view of manufacture method of describing the transparency electrode of luminescent device according to a preferred embodiment of the invention;
At first, the first metal layer 1102 be formed on the P type based on GaN the layer 1101 for example P-(In, Al) on the GaN layer, transparency electrode will form thereon.Wherein, described the first metal layer 1102 be from have with the good affinity of hydrogen and with form the P type based on the material of the layer 1101 of GaN for example GaN have select in the metal (especially, have with the hypoergia of N metal) of hypoergia a kind of.
In addition, second metal level 1103 is formed on the first metal layer 1102.At this moment, second metal level 1103 is the materials that form metal dots shape (referring to the conduction material arranged of Fig. 8) in the oxide of selecting that can easily form in the back.This also will describe in the back again.
In addition, the 3rd metal level 1104 is additionally formed on second metal level 1103.Here, described the 3rd metal level 1104 is materials of a kind of selection, easily form in its thermal annealing process of can be in the back carrying out with the first metal layer 1102 described mixed oxide layer (referring to Fig. 8 504).
So, as being used for described stacked process subsequently, described thermal annealing process (perhaps plasma process) is performed in oxygen-containing atmosphere.Therefore, following reaction is performed.
At first, the metal that forms described the first metal layer 1102 in described oxygen containing thermal annealing process (perhaps plasma process), absorb effectively be present in described P type based on the layer 1101 of GaN in hydrogen in the Mg-H labyrinth of existence.Therefore, described the first metal layer 1102 has the ' structure of (first metal)-oxide: H ' (metal oxide layer 503 of Fig. 8), and simultaneously, described P type is high concentration P types based on the layer of GaN (Fig. 8 502) and P type based on the layer of GaN (Fig. 8 501) based on the layer 1101 of GaN.
Therewith together, because forming the metal of the first metal layer 1102 has and forms described P type based on the material of the layer 1101 of the GaN hypoergia of GaN for example, so be difficult to form metal-nitride as ' (first metal)-nitride ', thereby obtain stable ohmic electrode structure.
In addition, described thermal annealing process causes at the part place of the 3rd metal level 1104 and described the first metal layer 1102 inter-diffusion reaction taking place, and makes heat-staple ' mixed oxide of (the 3rd metal)-(first metal) ' (Fig. 8 504) be formed.This allows hyaline layer with ' (first metal)-oxide: H ' layer (metal oxide layer 503 of Fig. 8) is formed, and is sent from described device well with the light that helps to produce in device.
In addition, the metal material that forms second metal level 1103 forms ' metal dots ' (referring to conduction material arranged 505 of Fig. 8) in the described oxide by described thermal annealing process.Described metal dots is served as ' conducting bridge ' so that have conductivity by the formed described oxide skin(coating) of described thermal annealing process, to help described transparency electrode 510 to serve as to be used to propagate ' the current spread device ' of described electric current.
Therewith together, because the size of described metal dots and density Be Controlled be so that the refractive index in the described oxide is conditioned, described photon sends from described device in can be more between short wavelength region so the function of photon path can be performed.
The invention described above can obtain following characteristic.
At first, have oxygen affinity and be used as described contact layer based on the metal material of hypoergia of the layer of GaN, so that the doping content at described P type nitride-based semiconductor place that is caused by described contact electrode layer is increased after described thermal annealing process effectively with the described P type that is formed on its underpart.Therefore, the ohmic contact of good quality can be implemented and since stable interface the raising of device reliability more can be expected.
In addition, the described TCB of serving as (TCO conducting bridge) ' metal dots ' is formed in the described whole oxide, so that described refractive index is regulated and described charge carrier conductive characteristic is easily improved.Therefore, be reduced, the light output of described device is increased significantly by the loss of the photon that in the described device that absorption and dispersion caused at described transparency electrode place, produces.
In addition, because double T CO mixed oxide self is very heat-staple, above structurized transparent configuration in described device, have good ' electric current-transmission device ', ' photon path ', ' to the absorption coefficient of interfacial energy ' function, make can the electricity of described luminescent device/structure/improvement of optical characteristics, obtain a lot of effects in the reliability safety etc.
On the other hand, as the concrete example of the material that forms each metal level, following material can be selected:
The first metal layer: Pd, Ir, Zn, and Ni
Second metal level: Au and Pt
The 3rd metal level: ZnO, IrO, Ir, Ni, Pd, Zn and V
Here, as the material that forms described the first metal layer, described metal is selected as wherein having good reactive described oxide simultaneously with hydrogen and is formed easily, and has with reactive metal of N selected hardly.This is that (In, Al) doping content that exists in the GaN layer is lowered the described P-that causes owing to compensation phenomenon, is difficult to form described ohm property because if form the material and the N reaction of described the first metal layer.
In addition, the material that forms second metal level is selected from the metal that can form described metal dots.
Described metal dots forms with following principle.That is to say, if form the metal of described oxide and not form the metal of described oxide stacked and by thermal annealing, the former forms described oxide, and does not form the metal of described oxide because the tension force phenomenon that the difference of surface heat energy causes and be in a shape naturally.Described metal dots helps described oxide to have described conductivity, and the size Be Controlled of described metal dots so that the refractive index of described oxide can be conditioned.At this moment, can form every layer thickness by changing, the time of thermal annealing and temperature, atmosphere gas waits size and the density of controlling described metal dots.
Form the material of described the first metal layer and form the material of described second metal level and the enthalpy energy of oxygen (KJ/mole of atom) is expressed as followsin.That is to say that Pd, Ir, Zn and Ni are the metals that wherein forms oxide easily, and its enthalpy energy meter indicating value is Pd-O-(56), Ni-O (120), Ir-O (80), Zn-O (174).
In addition, Au and Pt are the metals that wherein is difficult to form oxide, and its enthalpy energy meter indicating value is Au-O (10), Pt-O (+value).
In addition, described the 3rd metal level is, as mentioned above, selects from the metal that forms described first electrode layer and the metal that can easily form described mixed oxide layer.
If, in the superincumbent material, Ir is used as first electrode layer and is deposited on described P-(In, Al) on the GaN layer, and Au is used as the second electrode lay and is deposited on described first electrode layer, and ZnO is deposited as third electrode layer and thermal annealing and is performed at 550 ℃ in oxygen atmosphere subsequently, and following layer is formed.
P-(In，Al)GaN/P
+-(In，Al)GaN/IrO:H/Ir-ZnO
(Au is present in the described oxide with metal dots shape)
Here, (Ir=4.7eV, IrO:H 〉=5.4eV), described P type ohm forms and can be helped greatly to have big metal work function owing to IrO:H compares with Ir.
In addition, the moment heat that produces described oxide/stability of structure obtained, and described oxide has the structure of polycrystalline usually, has the relation with the extension of GaN simultaneously.
Therefore, the described Ir-ZnO mixed oxide layer that is formed on the top is helped to have same heteroepitaxy relation.
This photon that helps to produce in described optical device can send from described device well.Therewith together, because described stable electrode interface can be formed, the reliability of described electrode can be enhanced a lot.
Hereinafter, P type according to the present invention is based on the compound semiconductor (p-(Al) of gallium nitride
x(In)
y(Ga)
1-(x+y)The object lesson of the forming process of Ohmic electrode N) will be described.
The first Ohmic electrode formation method
Described P type is based on the compound (p-(Al) of gallium nitride
x(In)
y(Ga)
1-(x+y)N) semiconductor uses trichloroethylene (TCE) in ultrasonic cleaning machine, acetone, and methyl alcohol, and distilled water carried out surface clean 5 minutes 60 ℃ temperature.In addition, in order to remove the compound (p-(Al) of P type based on gallium nitride
x(In)
y(Ga)
1-(x+y)N) the described native oxide layer in the semiconductor is used to carrying out surface treatment 10 minutes to remove described native oxide layer based on the BOE of the wet solution of fluorine with the method for boiling.
Afterwards, use electron beam deposition equipment to be deposited as respectively and good reactive metal platinum (Pt) and titanium (Ti) are arranged as described contact layer with hydrogen.
Figure 16 and 17 is charts of the result of the explanation SIMS depth analysis that is used to confirm platinum-hydrogen compound layer that the first Ohmic electrode formation method of the luminescent device by according to a preferred embodiment of the invention forms and titanium-hydrogen compound layer;
The second Ohmic electrode formation method
Removing the compound (p-(Al) of P type based on gallium nitride with the method identical with the first Ohmic electrode formation method
x(In)
y(Ga)
1-(x+y)N) after the described natural oxide layer in the semiconductor, (circular transmission line model, C-TLM) pattern uses photoetching technique to form to circle-transmission line model, and carries out metal deposition subsequently.In described deposition, the platinum (Pt) that has 20nm thickness with the pressure deposition of about 10-7 holder is as contact layer, and is deposited as with gold (Au) that oxygen has a hypoergia and has 20nm thickness as described joint sheet layer.Afterwards, use acetone to carry out stripping technology, so that it is manufactured to have an Ohmic electrode of TLM (transmission line model) pattern.
Figure 18 is the view that the I-E characteristic of the Ohmic electrode that the second Ohmic electrode formation method of luminescent device according to a preferred embodiment of the invention makes is used in explanation.
The 3rd Ohmic electrode formation method
After the described second Ohmic electrode formation method is all finished, the nitrogen in stove, air was carried out described thermal annealing one minute at 600 ℃ in oxygen or the argon atmospher, to find ohmic conditions.
Figure 19 illustrates that thermal annealing wherein forms the view of the I-E characteristic of the Ohmic electrode that method carries out by the 3rd Ohmic electrode of luminescent device, and Figure 20 is result's the view of the feature contact resistance of the explanation passage that relies on the thermal annealing time in the 3rd Ohmic electrode formation method of described luminescent device.
Referring to Figure 19 and 20, be appreciated that by the described good ohmic contact characteristic of said process to be obtained.Especially, be understandable that described feature contact resistance value has reached less than 10
-5Ω cm
2
The 4th Ohmic electrode formation method
Described the 4th Ohmic electrode formation method is almost identical with the described second Ohmic electrode formation method, but its difference only is that titanium (Ti) replaces platinum (Pt) and is deposited as described contact layer.
Figure 21 is the view that the I-E characteristic of the Ohmic electrode that the 4th Ohmic electrode formation method of luminescent device makes is used in explanation.
The 5th Ohmic electrode formation method
In order after described the 4th Ohmic electrode forming process is all finished, to find described ohmic conditions, the nitrogen of the 5th Ohmic electrode formation method in described stove, air was carried out described thermal annealings one minute at 600 ℃ in oxygen or the argon atmospher.
Figure 22 illustrates that thermal annealing wherein forms the view of the I-E characteristic of the Ohmic electrode that method carries out by the 5th Ohmic electrode, and Figure 23 is result's the view of the feature contact resistance of the explanation passage that relies on the thermal annealing time in the 5th Ohmic electrode formation method.
Referring to Figure 22 and 23, be appreciated that by the described good ohmic contact characteristic of top process to be obtained.
Hereinafter, the sheet resistance value of the described Ohmic electrode in spirit according to the present invention and traditional sheet resistance value are compared with each other to describe.
Figure 24 is the view of variation that the sheet resistance value of Ohmic electrode according to a preferred embodiment of the invention is described;
Referring to Figure 24, be understandable that the compound (p-(Al) of P type based on gallium nitride
x(In)
y(Ga)
1-(x+y)N) carrier concentration in the semiconductor is caused by forming of described compound metal hydroxide layer.
For example, be removed with native oxide layer wherein and the sheet resistance value of traditional Ohmic electrode that described metal-hydrogen compound layer does not form relatively, sheet resistance value lower in the Ohmic electrode that has according to metal-hydrogen compound layer of the present invention is in sight.
Described not only described platinum-hydrogen compound and the described titanium-hydrogen compound of illustrating forms by the method that described embodiment proposes, and the variation of described nickel-hydrogen compound and described palladium-hydrogen compound described sheet resistance value when also forming with the same terms.
Figure 25 is a view of describing the electrode manufacturing method of luminescent device according to another embodiment of the present invention;
Here, it is characterized in that described P type electrode and described N type electrode are not only formed respectively, and described P type electrode and described N type electrode form together with identical process.
At first, description will be wherein as shown in Figure 6 the P type electrode of ' opening ' electrode structureization and the process that N type electrode as shown in Figure 14 is formed simultaneously.
As shown in Figure 25, the first metal layer 1202 is formed on P-(In, Al) (In is Al) on the GaN layer 1201 for GaN layer and N-.Here, (In, Al) GaN layer 1201 is the zones that wherein form described P type electrode to described P-, described N-(In, Al) zone of the described N type electrode of GaN layer 1201 expression wherein formation.
Additionally, second metal level 1203 that is formed by the material based on Al is formed on the described the first metal layer 1202.
In addition, the 3rd metal level 1204 is formed on described second metal level 1203, and the antioxidation coating 1205 of conduction is additionally formed on described the 3rd metal level 1204.
Here, the material that forms described the first metal layer 1202 is metal or has compound with the high response of Ga and N.In addition, the material that forms described the 3rd metal level 1204 is metal or the compound that has with the high response of Al, and is that material with the antioxidation coating 1205 that forms described conduction does not have reactive metal or compound.
Hereinafter, the material as a result of preceding step is carried out described thermal annealing, the described P type electrode of luminescent device proposed by the invention and described N type electrode can be formed simultaneously.
If like this, each layer that forms by described thermal annealing process will be described particularly.
By described thermal annealing process, described P-(In, Al) the GaN layer (referring to Fig. 6 401) and described N-(In, Al) the GaN layer (referring to Figure 14 1001) top by respectively by described P
+-(In, Al) GaN layer 402 and described N
+-(In, Al) GaN layer 1002 forms.
In addition, described first metal-Ga compound layer 403 is formed on described P
+-(In, Al) on the GaN layer 402, and described first metal-Ga-N compound layer 1003 is formed on described N
+-(In is Al) on the GaN layer 1002.
In addition, described the first metal layer 404 and 1004 is formed on described first metal-Ga compound layer 403 and the described first metal-Ga-N compound layer 1003, and described the 3rd metal- Al compound layer 405 and 1005 is formed on described the first metal layer 404 and 1004.In addition, the antioxidation coating 406 and 1006 of described conduction is provided on described the 3rd metal- Al compound layer 405 and 1005.
On the other hand, the first metal layer 1202 as shown in Figure 25 is the layers that are used to form diffusion barrier, described diffusion barrier is introduced into the described P-(In in upper metal element that suppresses described the first metal layer 1202 when described thermal annealing process is performed and the described P type electrode, Al) reaction at the interface of GaN layer 1201 is to form described ohm property.In addition, described the first metal layer 1202 have with described N type electrode in Ga and the good response characteristic of N, therefore and it is at the interface described to cause described (first metal)-(Ga)-N compound layer 1003 to be formed on, with the contact performance of described electrode layer be good.
The described P type electrode and the described N type electrode that form according to top basic concept have following structural change generation by described thermal annealing process.
At first, (In, the Al) Ga of GaN layer 1201 reaction is to convert the bilayer of first metal-Ga compound layer 403/ the first metal layer 404 to form the material of described the first metal layer 1202 and described P-.Wherein, formed bilayer serves as first diffusion barrier, is used for after described second metal level 1203 suppressing and the reacting to each other of described semiconductor and described upper electrode material.
Simultaneously, (In, Al) GaN layer 1201 is converted into P-(In, Al) GaN layer 401/P to described P-
+-(In, Al) the GaN layer 402.Top Structure Conversion finish be because by forming of described first metal-Ga compound layer 403 caused (In, Al) being led in the described P type nitride-based semiconductor served as in the Ga room that forms in the GaN layer 401 at described P-.
Simultaneously, (In, Al) GaN nitrogen room causes the formation of described first metal-Ga-N compound layer 1003 to N-, thereby has increased the carrier concentration on approaching surface, makes N-(In, Al) the GaN layer 1001/N of described conversion
+-(In, Al) GaN layer 1002 structure are obtained.
In addition, as the Al of the material that forms described second metal level 1203 and described the 3rd metal reaction of the material of described the 3rd metal level 1204 of conduct formation, described the 3rd metal- Al compound layer 405 and 1005 is formed.In addition, described the 3rd metal- Al compound layer 405 and 1005 serves as second diffusion barrier, be used to suppress form material and described bottom electrode and described semi-conductive undesirable reaction of the antioxidation coating 1205 of described conduction, and finally be used to increase the thermal stability of described electrode.
The material that is used to form the antioxidation coating 1205 of described conduction prevents the contaminated materials such as the oxygen that are easy to generate in described thermal annealing and other processes subsequently, water etc. invade described electrode.
In addition, the antioxidation coating 1205 of described conduction is a high conductive material, makes described charge carrier be incorporated into described electrode well from the outside, and therefore be in order to the heat that increases described electrode surface/material of the stability of chemistry.
Simultaneously, above-described each metal level can be following material.
The first metal layer: Cr, V or W
Second metal level: Al or Ni-Al
The 3rd metal level: Ni, Pt or Pd
The antioxidation coating of conduction: Au or by two kinds or more kinds of many-metal or compound layer that constitutes comprising Au
Here, form the Cr of described the first metal layer, V, W have with described P-GaN layer in the good reactivity of Ga, and have with the N-GaN layer in the good reactivity of N.Like this, why, same the reaction of metal in described P-GaN layer and N-GaN layer different reasons mutually be owing to be formed on the electronegativity at metal-semiconductor interface place and the difference between the interfacial energy.
That is to say that described Cr, V, W metal are the reactive metals that has with Ga and N.At this moment, the material that is reacted is distinguished for above-mentioned reasons, and making described reaction result is different in described P-GaN layer and N-GaN layer.
Reactive ' the thermosetting enthalpy energy ' of representing every kind of material is as follows.
P type electrode
Cr-Ga :-20 of atom arrives-30KJ/mole
V-Ga: atom-67KJ/mole
W-Ga: atom-1KJ/mole
N type electrode
Cr-(Ga)-N: atom-35KJ/mole
V-(Ga)-N: atom-40KJ/mole
W-(Ga)-N: atom-24KJ/mole
In addition, the described diffusion barrier that comprises Al has a structure, wherein it can be formed earlier when room temperature deposition that [reason is that NiAl is (at 298K atom-38KJ/mole), PtAl (the 298K atom-100KJ/mole), PdAl (the 373K atom-84KJ/mole)], and by described thermal annealing, more perfect metal-Al compound is formed.
For example, if by using electron-beam evaporator, Cr, Al, Ni, Au sequentially are deposited on the semiconductor structure of the described luminescent device of structure, and the Cr/Al/Ni/Au structure is obtained under described room temperature, and described thermal annealing is performed in nitrogen-containing atmosphere gas at 520 ℃, and electrode structure proposed by the invention can be formed.
Simultaneously, because it is similar to form the process and the top description of the P type electrode of described ' opening ' electrode structureization as shown in Figure 7 and N type electrode as shown in figure 14 simultaneously, detailed description is omitted.
But, the P type electrode of described in order to form ' sealing ' electrode structureization, described P type transparent electrode layer (referring to Fig. 7 410) be additionally formed that (In is Al) between GaN layer 1201 and the described the first metal layer 1202 at described P-.That is to say, described P type transparent electrode layer 410 be formed on described P-(In, Al) on the GaN layer 1201 after, described the first metal layer 1202, described second metal level 1203, the antioxidation coating 1205 of described the 3rd metal level 1204 and described conduction is stacked and subsequently by thermal annealing.
In addition, the described electrode structure that proposes among the present invention not only can be applied to NP type luminescent device and NPN type luminescent device, and can be applied directly to use described (In, Al) semi-conductive other electronic devices of GaN, opto-electronic device etc.
Specifically, in one pole n channel device (HEMT, MISFET, MESFET etc.), electrode proposed by the invention can be applied to source and drain electrode, and in the p channel device, can be applied to gate electrode.
In addition, even under the situation of bipolar device, can directly be applied to emitter, base stage, collector electrode according to NPN or positive-negative-positive structure.In addition, as ohm or Schottky electrode even can be applied to the electrode of photodetector.
The present invention can implement to take place simultaneously the Ohmic electrode of type, is used for satisfying described P type Ohmic electrode and N type Ohmic electrode characteristic simultaneously by an electrode structure, is different from wherein to form the N type that is applied to traditional luminescent device separately and the method for P type electrode.
In addition, in the present invention, compare with traditional electrode described electrode heat/stability of structure improved greatly, reason is above-mentioned described P type electrode as first diffusion barrier ' first metal-Ga compound layer 403/ the first metal layer 404 ' and described N type electrode ' first metal-Ga-N compound layer 1003 ', and as ' the 3rd metal-Al compound layer 405 and 1005 ' and ' antioxidation coating 406 of conduction and 1006 ' stability of second diffusion barrier.
In addition, described electrode have good electricity/heat/characteristic of structure, help to improve the reliability of described luminescent device, and this can increase device lifetime greatly.
In addition, because the present invention has the effect that increases the actual current density that described device injects, the reducing and can be realized effectively of the cut-in voltage of described device, thus reduce the power consumption of device.
Industrial applicability
As described above, have advantage according to optical device of the present invention and manufacture method thereof, its be electricity/heat/stability of structure obtained, and P type electrode and N type electrode can be formed simultaneously.
In addition, the invention has the advantages that P type electrode and N type electrode can be formed simultaneously, thereby simplify manufacture process, and reduce cost.
In addition, the feature contact resistance in the described transparency electrode is lowered, and uses the resistance of described reduction to carry out the propagation of the electric current of rule in described device from the charge carrier of outside supply.
In addition, the photon that produces in the described device and send can be allowed to escape into well the outside.
In addition, described metal-hydrogen compound layer is formed in the described Ohmic electrode, makes the compound (p-(Al) of described P type based on gallium nitride
x(In)
y(Ga)
1-(x+y)N) good Ohmic electrode can be implemented.
In described embodiment of the present invention, the described electrode structure and the manufacture method thereof of described luminescent device are described, but they not only can be applied to described luminescent device, and can be applied directly to the described (In of use, Al) semi-conductive other devices of GaN, opto-electronic device etc.
Its preferred embodiment is described and explanation although the present invention has been referenced, and clearly can carry out various modifications and variations without departing from the spirit and scope of the present invention concerning the people who is familiar with this technology.Therefore, the objective of the invention is to cover all modifications and the variation of this invention in the scope of claims and equivalent thereof.
Claims (17)
1. optical device comprises:
The one P type is based on the layer of GaN;
The 2nd P type is based on the layer of GaN, and its hole concentration is higher than the concentration of a described P type based on the hole of the layer of GaN, and is formed on the layer of a described P type based on GaN;
First metal-Ga compound layer is formed on the layer of described the 2nd P type based on GaN;
The first metal layer is formed on described first metal-Ga compound layer;
The 3rd metal-Al compound layer is formed on the described the first metal layer; And
The antioxidation coating of conduction is formed on described the 3rd metal-Al compound layer.
2. optical device comprises:
The one N type is based on the layer of GaN;
The 2nd N type is based on the layer of GaN, and its electron concentration is higher than the concentration of a described N type based on the electronics of the layer of GaN, and is formed on the layer of a described N type based on GaN;
First metal-Ga-N compound layer is formed on the layer of described the 2nd N type based on GaN;
The first metal layer is formed on described first metal-Ga-N compound layer;
The 3rd metal-Al compound layer is formed on the described the first metal layer; And
The antioxidation coating of conduction is formed on described the 3rd metal-Al compound layer,
Wherein, described the first metal layer is one that selects from the group that comprises V and W.
3. optical device as claimed in claim 1, wherein said the first metal layer are one that selects from the group that comprises Cr, V and W.
4. optical device as claimed in claim 1 or 2, wherein said the first metal layer are metal or the compounds that has high response with Ga and N.
5. optical device as claimed in claim 1 or 2, wherein said the 3rd metal are one that selects from the group that comprises Ni, Pt and Pd.
6. optical device as claimed in claim 1 or 2, wherein said the 3rd metal are metal or the compounds that has high response with Al.
7. optical device as claimed in claim 1 or 2, wherein said the 3rd metal are that the material with the antioxidation coating that forms described conduction does not have reactive metal or compound.
8. optical device as claimed in claim 1 or 2, the antioxidation coating of wherein said conduction is Au, or two kinds or the two or more many metals that contain the element formation of Au, or two or more contains the compound of element formation of Au.
9. optical device as claimed in claim 1, wherein, described the 2nd P type is higher than 10 based on layer hole concentration that is had of GaN
18Cm
-3Perhaps be higher than the hole concentration of a described P type based on the lower area of the layer of GaN.
10. optical device as claimed in claim 2, wherein, described the 2nd N type is higher than 10 based on layer electron concentration that is had of GaN
18Cm
-3Perhaps be higher than the electron concentration of a described N type based on the lower area of the layer of GaN.
11. an optical device manufacturing method, it may further comprise the steps:
Form the layer of a P type based on GaN;
On the layer of a P type, form the first metal layer based on GaN;
On the first metal layer, form material based on Al;
Form the 3rd metal level described on based on the material of Al;
On the 3rd metal level, form the antioxidation coating of conduction;
The above-mentioned material that obtains is carried out thermal annealing,
Form the layer of the 2nd P type based on GaN between a P type is based on the layer of GaN and the first metal layer, described the 2nd P type is higher than the hole concentration of a P type based on the layer of GaN based on the hole concentration of the layer of GaN;
Between the 2nd P type is based on the layer of GaN and the first metal layer, form first metal-Ga compound layer;
On the first metal layer, form the 3rd metal-Al compound layer.
12. an optical device manufacturing method, it may further comprise the steps:
Form the layer of a N type based on GaN;
On the layer of a N type, form the first metal layer based on GaN;
On the first metal layer, form material based on Al;
Form the 3rd metal level described on based on the material of Al;
On the 3rd metal level, form the antioxidation coating of conduction;
The above-mentioned material that obtains is carried out thermal annealing,
Form the layer of the 2nd N type based on GaN between a N type is based on the layer of GaN and the first metal layer, described second electron concentration based on the layer of GaN is higher than the electron concentration of a N type based on the layer of GaN;
Between the 2nd N type is based on the layer of GaN and the first metal layer, form first metal-Ga-N compound layer;
On the first metal layer, form the 3rd metal-Al compound layer,
Wherein, described the first metal layer is one that selects from the group that comprises V and W.
13. manufacture method as claimed in claim 11, wherein said the first metal layer are one that selects from the group that comprises Cr, V and W, the antioxidation coating of described conduction is Au, or two kinds or two or more many metals or the compound that contains the element formation of Au.
14. as claim 11 or 12 described manufacture methods, the material that wherein forms described the 3rd metal is one that selects from the group that comprises Ni, Pt and Pd, described the first metal layer is one that selects from the group that comprises Cr, V and W.
15. manufacture method as claimed in claim 11, wherein, described the 2nd P type is higher than 10 based on the hole concentration of the layer of GaN
18Cm
-3
16. manufacture method as claimed in claim 12, wherein, described the 2nd N type is higher than 10 based on the electron concentration of the layer of GaN
18Cm
-3
17. manufacture method as claimed in claim 12, wherein, the antioxidation coating of described conduction is Au, or two kinds or two or more many metals or the compound that contains the element formation of Au.
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| KR10-2002-0071432 | 2002-11-16 | ||
| KR1020020071432A KR100550735B1 (en) | 2002-11-16 | 2002-11-16 | Eletrode structure of P-AlInGaN semiconductor and forming method thereof |
| KR1020020071432 | 2002-11-16 | ||
| KR10-2003-0058210 | 2003-08-22 | ||
| KR1020030058210 | 2003-08-22 | ||
| KR1020030058209 | 2003-08-22 | ||
| KR20030058209A KR100632668B1 (en) | 2003-08-22 | 2003-08-22 | Transparent electrode of LED and fabrication method thereof |
| KR20030058210A KR100632669B1 (en) | 2003-08-22 | 2003-08-22 | LED and fabrication method thereof |
| KR10-2003-0058209 | 2003-08-22 | ||
| PCT/KR2003/002468 WO2004047189A1 (en) | 2002-11-16 | 2003-11-17 | Light emitting device and fabrication method thereof |
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Cited By (1)
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Families Citing this family (5)
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| US9581870B2 (en) | 2009-08-13 | 2017-02-28 | 3M Innovative Properties Company | Conducting film or electrode with improved optical and electrical performance for display and lighting devices and solar cells |
| KR101731056B1 (en) | 2010-08-13 | 2017-04-27 | 서울바이오시스 주식회사 | Semiconductor light emitting device having ohmic electrode structure and method of fabricating the same |
| US9287459B2 (en) * | 2014-02-14 | 2016-03-15 | Epistar Corporation | Light-emitting device |
| US9673368B2 (en) * | 2015-05-11 | 2017-06-06 | Lg Innotek Co., Ltd. | Light emitting device having first and second electrodes on one side of a light emitting structure |
| KR102313029B1 (en) | 2019-12-30 | 2021-10-13 | 홍익대학교 산학협력단 | Electrode forming method for semiconductor device and electrode structure formed by the method |
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| JP3519950B2 (en) * | 1994-07-19 | 2004-04-19 | シャープ株式会社 | Electrode structure |
| JPH0832115A (en) * | 1994-07-19 | 1996-02-02 | Sharp Corp | Electrode structure and its manufacture |
| JP4292619B2 (en) * | 1999-03-24 | 2009-07-08 | パナソニック株式会社 | Manufacturing method of semiconductor device |
| JP2002075910A (en) * | 2000-08-24 | 2002-03-15 | Sharp Corp | Method of manufacturing electrode structure for nitride-based iii-v compound semiconductor device |
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| Title |
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| JP特开2001-15852A 2001.01.19 |
| N.A.Papanicolaou,A.Edwards,M.V.Rao,J.Mittereder and W.T.Anderson.Cr/Al and Cr/Al/Ni/Au ohmic contacts to n-type GaN.《Journal of Applied Physics》.2000,第87卷(第1期),380-385. * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102916103B (en) * | 2012-09-18 | 2017-05-03 | 中山大学 | Thin film structure transparent electrode and preparation method thereof |
Also Published As
| Publication number | Publication date |
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| CN1711649A (en) | 2005-12-21 |
| KR100550735B1 (en) | 2006-02-08 |
| KR20040043244A (en) | 2004-05-24 |
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